/*
 * SPDX-FileCopyrightText: 2021 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

// #define LOG_LOCAL_LEVEL ESP_LOG_DEBUG

#include <stdlib.h>
#include <sys/cdefs.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_lcd_panel_interface.h"
#include "esp_lcd_panel_io.h"
#include "esp_lcd_panel_vendor.h"
#include "esp_lcd_panel_ops.h"
#include "driver/gpio.h"
#include "esp_log.h"
#include "esp_check.h"

#include "esp_lcd_panel_st7796.h"

static const char *TAG = "lcd_panel.st7796";

static esp_err_t panel_st7796_del(esp_lcd_panel_t *panel);
static esp_err_t panel_st7796_reset(esp_lcd_panel_t *panel);
static esp_err_t panel_st7796_init(esp_lcd_panel_t *panel);
static esp_err_t panel_st7796_draw_bitmap(esp_lcd_panel_t *panel, int x_start, int y_start, int x_end, int y_end, const void *color_data);
static esp_err_t panel_st7796_invert_color(esp_lcd_panel_t *panel, bool invert_color_data);
static esp_err_t panel_st7796_mirror(esp_lcd_panel_t *panel, bool mirror_x, bool mirror_y);
static esp_err_t panel_st7796_swap_xy(esp_lcd_panel_t *panel, bool swap_axes);
static esp_err_t panel_st7796_set_gap(esp_lcd_panel_t *panel, int x_gap, int y_gap);
static esp_err_t panel_st7796_disp_off(esp_lcd_panel_t *panel, bool off);

typedef struct {
    esp_lcd_panel_t base;
    esp_lcd_panel_io_handle_t io;
    int reset_gpio_num;
    bool reset_level;
    int x_gap;
    int y_gap;
    unsigned int bits_per_pixel;
    uint8_t madctl_val; // save current value of LCD_CMD_MADCTL register
    uint8_t colmod_cal; // save surrent value of LCD_CMD_COLMOD register
} st7796_panel_t;

esp_err_t esp_lcd_new_panel_st7796(const esp_lcd_panel_io_handle_t io, const esp_lcd_panel_dev_config_t *panel_dev_config, esp_lcd_panel_handle_t *ret_panel)
{
    esp_err_t ret = ESP_OK;
    st7796_panel_t *st7796 = NULL;
    ESP_GOTO_ON_FALSE(io && panel_dev_config && ret_panel, ESP_ERR_INVALID_ARG, err, TAG, "invalid argument");
    st7796 = calloc(1, sizeof(st7796_panel_t));
    ESP_GOTO_ON_FALSE(st7796, ESP_ERR_NO_MEM, err, TAG, "no mem for st7796 panel");

    if (panel_dev_config->reset_gpio_num >= 0) {
        gpio_config_t io_conf = {
            .mode = GPIO_MODE_OUTPUT,
            .pin_bit_mask = 1ULL << panel_dev_config->reset_gpio_num,
        };
        ESP_GOTO_ON_ERROR(gpio_config(&io_conf), err, TAG, "configure GPIO for RST line failed");
    }
 
    switch (panel_dev_config->color_space) {
    case ESP_LCD_COLOR_SPACE_RGB:
        st7796->madctl_val = 0;
        break;
    case ESP_LCD_COLOR_SPACE_BGR:
        st7796->madctl_val |= LCD_CMD_BGR_BIT;
        break;
    default:
        ESP_GOTO_ON_FALSE(false, ESP_ERR_NOT_SUPPORTED, err, TAG, "unsupported color space");
        break;
    }

    switch (panel_dev_config->bits_per_pixel) {
    case 16:
        st7796->colmod_cal = 0x55;
        break;
    case 18:
        st7796->colmod_cal = 0x66;
        break;
    default:
        ESP_GOTO_ON_FALSE(false, ESP_ERR_NOT_SUPPORTED, err, TAG, "unsupported pixel width");
        break;
    }

    st7796->io = io;
    st7796->bits_per_pixel = panel_dev_config->bits_per_pixel;
    st7796->reset_gpio_num = panel_dev_config->reset_gpio_num;
    st7796->reset_level = panel_dev_config->flags.reset_active_high;
    st7796->base.del = panel_st7796_del;
    st7796->base.reset = panel_st7796_reset;
    st7796->base.init = panel_st7796_init;
    st7796->base.draw_bitmap = panel_st7796_draw_bitmap;
    st7796->base.invert_color = panel_st7796_invert_color;
    st7796->base.set_gap = panel_st7796_set_gap;
    st7796->base.mirror = panel_st7796_mirror;
    st7796->base.swap_xy = panel_st7796_swap_xy;
    st7796->base.disp_on_off = panel_st7796_disp_off;
    *ret_panel = &(st7796->base);
    ESP_LOGD(TAG, "new st7796 panel @%p", st7796);

    return ESP_OK;

err:
    if (st7796) {
        if (panel_dev_config->reset_gpio_num >= 0) {
            gpio_reset_pin(panel_dev_config->reset_gpio_num);
        }
        free(st7796);
    }
    return ret;
}

static esp_err_t panel_st7796_del(esp_lcd_panel_t *panel)
{
    st7796_panel_t *st7796 = __containerof(panel, st7796_panel_t, base);

    if (st7796->reset_gpio_num >= 0) {
        gpio_reset_pin(st7796->reset_gpio_num);
    }
    ESP_LOGD(TAG, "del st7796 panel @%p", st7796);
    free(st7796);
    return ESP_OK;
}

static esp_err_t panel_st7796_reset(esp_lcd_panel_t *panel)
{
    st7796_panel_t *st7796 = __containerof(panel, st7796_panel_t, base);
    esp_lcd_panel_io_handle_t io = st7796->io;

    // perform hardware reset
    if (st7796->reset_gpio_num >= 0) {
        gpio_set_level(st7796->reset_gpio_num, st7796->reset_level);
        vTaskDelay(pdMS_TO_TICKS(10));
        gpio_set_level(st7796->reset_gpio_num, !st7796->reset_level);
        vTaskDelay(pdMS_TO_TICKS(10));
    } else { // perform software reset
        esp_lcd_panel_io_tx_param(io, LCD_CMD_SWRESET, NULL, 0);
        vTaskDelay(pdMS_TO_TICKS(20)); // spec, wait at least 5m before sending new command
    }

    return ESP_OK;
}

// #define CONFIG_ENABLE_LCD_TE    0

#ifdef CONFIG_ENABLE_LCD_TE

#include "freertos/event_groups.h"
#include "freertos/queue.h"

static xQueueHandle xQueue = NULL;

static const uint8_t LCD_TE_EVENT = BIT0;
static EventGroupHandle_t xEvent = NULL;    

typedef struct {
    esp_lcd_panel_io_handle_t io;
    int x_start;
    int y_start;
    int x_end;
    int y_end;
    const void *color_data;
} lcd_draw_bitmap_t;
 
static void IRAM_ATTR gpio_isr_handler(void* arg)
{
    BaseType_t xHigherPriorityTaskWoken, xResult;

    /* xHigherPriorityTaskWoken must be initialised to pdFALSE. */
    xHigherPriorityTaskWoken = pdFALSE;

    /* Set bit 0 and bit 4 in xEventGroup. */
    xResult = xEventGroupSetBitsFromISR( xEvent, LCD_TE_EVENT, &xHigherPriorityTaskWoken );

    /* Was the message posted successfully? */
    if ( xResult != pdFAIL ) {
        portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
    }
}

static bool lcd_te_event_wait(uint32_t wait_time)
{
    if (xEvent == NULL) return false;
    xEventGroupClearBits(xEvent, LCD_TE_EVENT);
    EventBits_t uxBits = xEventGroupWaitBits(xEvent, LCD_TE_EVENT, pdFALSE, pdFALSE, wait_time);
    if (uxBits & LCD_TE_EVENT) {
        return true;
    }
    return false;
}

static void lcd_refresh_task(void *arg)
{
    lcd_draw_bitmap_t lcd;
    while (true) {
        if (xQueueReceive(xQueue, &lcd, portMAX_DELAY) == pdTRUE) {  
            lcd_te_event_wait(portMAX_DELAY);
            
            // TickType_t start_time = xTaskGetTickCount();
            // define an area of frame memory where MCU can access
            esp_lcd_panel_io_tx_param(lcd.io, LCD_CMD_CASET, (uint8_t[]) {
                (lcd.x_start >> 8) & 0xFF,
                lcd.x_start & 0xFF,
                ((lcd.x_end - 1) >> 8) & 0xFF,
                (lcd.x_end - 1) & 0xFF,
            }, 4);
            esp_lcd_panel_io_tx_param(lcd.io, LCD_CMD_RASET, (uint8_t[]) {
                (lcd.y_start >> 8) & 0xFF,
                lcd.y_start & 0xFF,
                ((lcd.y_end - 1) >> 8) & 0xFF,
                (lcd.y_end - 1) & 0xFF,
            }, 4);

            // transfer frame buffer
            size_t len = (lcd.x_end - lcd.x_start) * (lcd.y_end - lcd.y_start) * 2;
            esp_lcd_panel_io_tx_color(lcd.io, LCD_CMD_RAMWR, lcd.color_data, len);  // Write frame memory

            // ESP_LOGI(TAG, "esp_lcd_panel time = %dms\n", xTaskGetTickCount() - start_time);
        }
    }
    
}
#endif

static esp_err_t panel_st7796_init(esp_lcd_panel_t *panel)
{
    st7796_panel_t *st7796 = __containerof(panel, st7796_panel_t, base);
    esp_lcd_panel_io_handle_t io = st7796->io;
    // LCD goes into sleep mode and display will be turned off after power on reset, exit sleep mode first
    esp_lcd_panel_io_tx_param(io, LCD_CMD_SLPOUT, NULL, 0);
    vTaskDelay(pdMS_TO_TICKS(100));

#ifdef CONFIG_ENABLE_LCD_TE  // 使能 TE 同步信号
    #define CONFIG_PIN_NUM_TE             48 
    // set as input/output mode
    gpio_set_direction(CONFIG_PIN_NUM_TE, GPIO_MODE_INPUT);
    // enable pull-up mode
    gpio_set_pull_mode(CONFIG_PIN_NUM_TE, GPIO_PULLUP_ONLY);
    // change gpio intrrupt type for one pin
    gpio_set_intr_type(CONFIG_PIN_NUM_TE, GPIO_INTR_POSEDGE);
    // install gpio isr service
    gpio_install_isr_service(0);  // ESP_INTR_FLAG_LEVEL6  
    // hook isr handler for specific gpio pin
    gpio_isr_handler_add(CONFIG_PIN_NUM_TE, gpio_isr_handler, NULL);

    xEvent = xEventGroupCreate();     // 设备消息事件组
    xQueue = xQueueCreate(3, sizeof(lcd_draw_bitmap_t));
    xTaskCreatePinnedToCore(lcd_refresh_task, "lcd_refresh_task", 3072, NULL, 16, NULL, APP_CPU_NUM);

    esp_lcd_panel_io_tx_param(io, LCD_CMD_TEON, (uint8_t[]) {
        0x00  /* When TEM =’0’: The Tearing Effect output line consists of V-Blanking information only */
              // When TEM =’1’: The Tearing Effect output Line consists of both V-Blanking and H-Blanking information 
    }, 1);
    #define TE_LINE     0
    esp_lcd_panel_io_tx_param(io, LCD_CMD_STE, (uint8_t[]) {
        (TE_LINE >> 8) & 0xFF,
        (TE_LINE & 0xFF)
    }, 2);
#endif
    // st7796->madctl_val = 0x48;
    esp_lcd_panel_io_tx_param(io, LCD_CMD_MADCTL, (uint8_t[]) {
        st7796->madctl_val,
    }, 1);
    esp_lcd_panel_io_tx_param(io, LCD_CMD_COLMOD, (uint8_t[]) {
        st7796->colmod_cal,
    }, 1);
    // turn on display
    esp_lcd_panel_io_tx_param(io, LCD_CMD_DISPON, NULL, 0);

    return ESP_OK;
}

static esp_err_t panel_st7796_draw_bitmap(esp_lcd_panel_t *panel, int x_start, int y_start, int x_end, int y_end, const void *color_data)
{
    st7796_panel_t *st7796 = __containerof(panel, st7796_panel_t, base);
    assert((x_start < x_end) && (y_start < y_end) && "start position must be smaller than end position");
    esp_lcd_panel_io_handle_t io = st7796->io;
  
    x_start += st7796->x_gap;
    x_end   += st7796->x_gap;
    y_start += st7796->y_gap;
    y_end   += st7796->y_gap;

#ifdef CONFIG_ENABLE_LCD_TE
    lcd_draw_bitmap_t lcd;
    lcd.x_start = x_start;
    lcd.x_end   = x_end;
    lcd.y_start = y_start;
    lcd.y_end   = y_end;
    lcd.color_data = color_data;
    lcd.io = io;
    xQueueSend(xQueue, &lcd, 0); 
#else  
    // define an area of frame memory where MCU can access
    esp_lcd_panel_io_tx_param(io, LCD_CMD_CASET, (uint8_t[]) {
        (x_start >> 8) & 0xFF,
        x_start & 0xFF,
        ((x_end - 1) >> 8) & 0xFF,
        (x_end - 1) & 0xFF,
    }, 4);
    esp_lcd_panel_io_tx_param(io, LCD_CMD_RASET, (uint8_t[]) {
        (y_start >> 8) & 0xFF,
        y_start & 0xFF,
        ((y_end - 1) >> 8) & 0xFF,
        (y_end - 1) & 0xFF,
    }, 4);

    // transfer frame buffer
    size_t len = (x_end - x_start) * (y_end - y_start) * st7796->bits_per_pixel / 8;
    esp_lcd_panel_io_tx_color(io, LCD_CMD_RAMWR, color_data, len);  // Write frame memory
#endif
    return ESP_OK;
}

static esp_err_t panel_st7796_invert_color(esp_lcd_panel_t *panel, bool invert_color_data)
{
    st7796_panel_t *st7796 = __containerof(panel, st7796_panel_t, base);
    esp_lcd_panel_io_handle_t io = st7796->io;
    int command = 0;
    if (invert_color_data) {
        command = LCD_CMD_INVON;
    } else {
        command = LCD_CMD_INVOFF;
    }
    esp_lcd_panel_io_tx_param(io, command, NULL, 0);
    return ESP_OK;
}

static esp_err_t panel_st7796_mirror(esp_lcd_panel_t *panel, bool mirror_x, bool mirror_y)
{
    st7796_panel_t *st7796 = __containerof(panel, st7796_panel_t, base);
    esp_lcd_panel_io_handle_t io = st7796->io;
    if (mirror_x) {
        st7796->madctl_val |= LCD_CMD_MX_BIT;
    } else {
        st7796->madctl_val &= ~LCD_CMD_MX_BIT;
    }
    if (mirror_y) {
        st7796->madctl_val |= LCD_CMD_MY_BIT;
    } else {
        st7796->madctl_val &= ~LCD_CMD_MY_BIT;
    }
    esp_lcd_panel_io_tx_param(io, LCD_CMD_MADCTL, (uint8_t[]) {
        st7796->madctl_val
    }, 1);
    return ESP_OK;
}

static esp_err_t panel_st7796_swap_xy(esp_lcd_panel_t *panel, bool swap_axes)
{
    st7796_panel_t *st7796 = __containerof(panel, st7796_panel_t, base);
    esp_lcd_panel_io_handle_t io = st7796->io;
    if (swap_axes) {
        st7796->madctl_val |= LCD_CMD_MV_BIT;
    } else {
        st7796->madctl_val &= ~LCD_CMD_MV_BIT;
    }
    esp_lcd_panel_io_tx_param(io, LCD_CMD_MADCTL, (uint8_t[]) {
        st7796->madctl_val
    }, 1);
    return ESP_OK;
}

static esp_err_t panel_st7796_set_gap(esp_lcd_panel_t *panel, int x_gap, int y_gap)
{
    st7796_panel_t *st7796 = __containerof(panel, st7796_panel_t, base);
    st7796->x_gap = x_gap;
    st7796->y_gap = y_gap;
    return ESP_OK;
}

static esp_err_t panel_st7796_disp_off(esp_lcd_panel_t *panel, bool off)
{
    st7796_panel_t *st7796 = __containerof(panel, st7796_panel_t, base);
    esp_lcd_panel_io_handle_t io = st7796->io;
    int command = 0;
    if (off) {
        command = LCD_CMD_DISPOFF;
    } else {
        command = LCD_CMD_DISPON;
    }
    esp_lcd_panel_io_tx_param(io, command, NULL, 0);
    return ESP_OK;
}
